[FEATURES] Support hierarchical imagePullSecrets configuration in JuiceFSRuntime CRD

[cheyang]

What feature you'd like to add: We request the enhancement of the JuiceFSRuntime to support hierarchical imagePullSecrets configuration. Specifically, we want to be able to specify imagePullSecrets at two levels:

1. Global level under spec
2. Component level a. Worker component level under spec.worker b. FUSE component level under spec.fuse

apiVersion: data.fluid.io/v1alpha1
kind: JuiceFSRuntime
metadata:
  name: hbase
spec:
  replicas: 2
  imagePullSecrets: 
    - name: test-1
    - name: test-2
  tieredstore:
    levels:
      - mediumtype: MEM
        path: /dev/shm
        quota: 2Gi
        high: "0.95"
        low: "0.7"
  worker:
    imagePullSecrets: 
    - name: test-1
    - name: test-2
  fuse:
    imagePullSecrets: 
    - name: test-1
    - name: test-2

Why is this feature needed: This feature will provide greater flexibility for users who need to manage different image pull secrets for various components of their JuiceFSRuntime. For example, users might have different private registries or credentials for the master and worker components. This hierarchical configuration will allow for more granular control and easier management of image pull secrets in complex deployment environments.